For his final graduate thesis, Jesús Sánchez, an industrial-design student at the Universitat Politècnica de Catalunya, invented an elegant solution to the problem of mobility for the disabled, which he expects would pay for itself by reducing operating costs by 35%.

The most obviously clever part of the design is its steps. Normally, the escalator’s steps are of a standard width. But at the push of a button, three steps come together, to create a platform that’s perfectly sized for a wheelchair.

As Sánchez points out, such a dual-purpose escalator could present significant cost savings for builders who would otherwise have to install an elevator. But that’s only where the savings begin. Most escalators are discrete from one another–the up escalator doesn’t share any systems with the down escalator next to it. But Sánchez designed a linkage that allows the up and down escalators to run on the same belt, gaining operating efficiency. The trick was engineering steps that could make the turn at the top and bottom of the escalator bank–much like the kinks you see on the baggage conveyor belts at the airport.

Sánchez, who already holds a patent on the design, is now seeking out investors who’ll commercialize his idea.